Various types of timers have been provided heretofore to measure or indicate short periods of time such as the three minute period for telephone toll calls. These devices have included invertible short time timers of the hourglass type, timers with gravity actuated escapements, clockwise timers, and other spring operated devices. These devices have provided various forms of indicators and include audible alarms to indicate the passage of time. It is desirable to produce a timer device to apprise the user of the telephone of the passage of a major portion of the time and which will indicate the approach of the end of the time period for the call. It is also desirable to provide a timing device which may be observed at a distance and enable a supervisor of a group of telephone users to determine the effectiveness of the users in maintaining their calls within a predetermined time period. Accordingly, it is an object of the invention to provide a timer for telephone toll calls and the like including an improved arrangement for readily and reliably apprising the user of the passage of time.
It is another object of this invention to provide a timer for telephone toll calls and the like including indicators of the initiation of the use of the timer, of the passage of a predetermined measured portion of the time and of the approach of the full time period, and further which may readily be observed at a distance for monitoring the use of the telephone.